/Engine/Source/Runtime/MeshDescription/Public/MeshDescriptionBase.h
Return reference to an array of triangle IDs which comprise this polygon
void GetPolygonTriangles ( [FPolygonID](API\Runtime\MeshDescription\FPolygonID) PolygonID, [TArray](API\Runtime\Core\Containers\TArray)< [FTriangleID](API\Runtime\MeshDescription\FTriangleID) > & OutTriangleIDs ) const